upstream tomcat  {
{% for host in groups['backend_servers'] %}
        server {{ host }}:{{ tomcat_http_port }};
{% endfor %}
}

server {
    listen       80 default_server;
    # server_name  {{ inventory_hostname }};
    # include /etc/nginx/default.d/*.conf;

    location / {
        proxy_pass http://tomcat;
    }

}